1. Field of the Invention
The present invention is in the field of security devices and specifically relates to a locking assembly that can be used to deny access to a nut or to a bolt head, to prevent theft of an article through which the bolt passes.
2. The Prior Art
The purpose of the locking assembly is to prevent an otherwise exposed nut or bolt head from being unscrewed without first unlocking and removing the locking assembly. The locking assembly surrounds the nut or bolt head that it protects. In the present invention, the locking assembly consists of two parts: a retainer through which the bolt passes, and an access-denying housing that locks onto the retainer by means of a lock included within the housing. Access to the nut or bolt head can be gained only by unlocking and removing the housing and this requires a key that is made available only to authorized users.
Devices of this general nature have long been used in the automotive field to prevent theft of spare wheels and other exposed accessories.
In a contemporary example distributed in the United States by Carrani Companies, Inc. of Gardena, Cal., a wheel lug nut holds a retainer and the wheel to be protected on a stud, and a housing fits over the wheel lug nut and the retainer, and locks to the retainer by means of a lock that is included within the protective housing.
In its external appearance the Carrani device bears some similarity to the devices shown in the Trautner and in the Brunelli patent to be discussed below.
In U.S. Pat. No. 1,912,872, Trauntner shows a tire lock for use on motor vehicles, in which the axis of the lock is parallel to the axis of the bolt. As the key is turned, a finger is rotated to extend into a groove on a retainer portion.
In U.S. Pat. No. 3,423,971, Brunelli shows a lock for use on the wheel of an automobile, and as with the Trautner device, the axis of the lock is parallel to the axis of the bolt. Instead of a finger, Brunelli uses an offcenter cam which must past through a hole in a plate so as to retain the cover to the plate.
In U.S. Pat. No. 3,975,935, Masterson shows a removable plastic case for protecting a locking device from the weather. The locking device includes a tang that is operated by a keeper.
In U.S. Pat. No. 3,525,242, Young shows a bolt that uses ball bearings but in his lock the locking mechanism extends from and is coaxial with the bolt. In Young's device, the end of the bolt must have a groove for the ball bearings that he uses. Consequently, his device cannot be used to protect a standard nut or bolt.
In U.S. Pat. No 1,870,427, Stallings, et al. show a lock which serves as a nut and must therefore be hexagonal. The lock is coaxial with the axis of the stud and extends from it. This gives the lock a high profile, making it easier to break off.
In U.S. Pat. No. 1,692,826, Ganz shows a lock that is coaxial with the bolt and extends from it. The device is not usable with a standard nut, and it appears that the bolt must include a groove near its end.
Unlike these prior art devices, in the present invention, the axis of the lock may be at any chosen angle with respect to the axis of the bolt. Also, the mechanism used in the present invention is extremely simple and reliable and these features have proven to be highly advantageous.